public SpreadsheetinvokerCE(Spreadsheet spreadsheet) {
    super(spreadsheet);
    IActivity[] cellActivities = new CellActivityBuilder(spreadsheet.getCells()).buildActivities();
    IScheduler scheduler = ServiceMT.getService().getScheduler(DEFAULT_CELL_TIME_NS);

    this.scheduledActivities = scheduler.prepare(cellActivities);
    this.scheduleExecutor = new ScheduleExecutor(scheduledActivities);
  }